DISSERTATION RESEARCH: Comparative Biomechanics of Sand Locomotion in Lizards

论文研究：蜥蜴在沙地运动的比较生物力学。科尔夫·马瓦利·H加州大学伯克利分校许多动物在风吹来的细沙上生活。 考虑到这一点，令人惊讶的是，人们对动物身体形态的元素知之甚少，这些元素可能有助于在沙滩上运动。就像雪鞋帮助人类在雪地上移动一样，以前的研究表明，拥有脚趾边缘（侧向突出的细长鳞片）的蜥蜴适合在沙子上奔跑，但这一假设尚未得到严格的验证。 在这项研究中，研究人员将研究三种密切相关的沙居蜥蜴的快速奔跑：莫哈韦流苏趾蜥蜴（Uma scorparia），以及斑马尾蜥蜴的非流苏加州（Callisaurus draconoides draconoides）和流苏墨西哥（Callisaurus draconoides crinitis）亚群。在这项工作中将解决两个一般性问题：1。蜥蜴脚趾上的流苏能帮助它们在沙地上奔跑吗和2.足部形状的变化如何影响力从动物到桑迪基底的传递？ 这项工作通过综合有机体生物学，进化生物学，机械工程和颗粒物理学领域来解决这些问题。 研究人员将使用能够每秒记录1000张图像的摄像机（标准摄像机每秒记录30张图像）来减缓动物在自然环境中的运动，因为它们在许多不同的基质上运行。 收集到的信息将被用来构建一个机器人附肢，代表许多不同种类蜥蜴脚形多样性的模型将被连接到这个附肢上。 通过在机器人控制的脚上“回放”现场记录的运动模式，研究人员将能够通过蜥蜴生活的基底测量不同脚形产生的力。 从这些研究中，可以直接测量脚形变化对推动动物前进的影响。 这项工作是第一次研究动物如何在不同的基质上奔跑，以及是否有特定的脚形可能更有效地在沙子上快速移动。

Dissertation Research: Comparative biomechanics of sand locomotion in lizardsWyatt L. KorffMarvalee H. WakeUniversity of California, Berkeley Many animals spend their lives on fine wind-blown sand. Given this, it is surprising that so little is known about the elements of an animal's body form that may aid in locomotion over sand. Much like snowshoes aid humans moving on snow, previous investigations have suggested that lizards that possess toe fringes (sideways projecting elongate scales) are adapted to running on sand, but this hypothesis has yet to be rigorously tested. In this study, the investigators will study the rapid running of three closely related sand dwelling lizards: the Mojave fringe-toed lizard (Uma scorparia), and non-fringed California (Callisaurus draconoides draconoides) and fringed Mexican (Callisaurus draconoides crinitis) subpopulations of the zebra-tailed lizard. Two general questions will be addressed in this work: 1. do fringes on the toes of lizards help them run on sand? and 2. how does variation in foot shape affect the transmission of forces from the animal to the sandy substrate? This work approaches these questions by synthesizing the fields of organismal biology, evolutionary biology, mechanical engineering, and granular physics. The researchers will use video cameras capable of recording 1000 images per second (standard cameras record at 30 images per second) to slow down the movement of animals in their natural environments as they run on a number of different substrates. Information gathered will be used to construct a robotic appendage to which models representing the diversity of foot shapes found in many different species of lizards will be attached. By "playing back" the movement patterns recorded in the field on the robotically controlled feet, the investigators will be able to measure the forces generated by different foot shapes through substrates where the lizards live. From these studies, the effect of changes in foot shape in propelling the animals forward can be directly measured. This work is one of the first to investigate how animals run on different substrates, and whether there are particular foot shapes that may be more effective for rapid movements on sand.